The temperature at which the spontaneous polarisation disappears is called the Curie temperature, TC.

Above 120°C, barium titanate has a cubic structure. This means it is centro-symmetric and possesses no spontaneous dipole. With no dipole the material behaves like a simple dielectric, giving a linear polarisation. TC for barium titanate is 120°C.

Below 120°C, it changes to a tetragonal phase, with an accompanying movement of the atoms. The movement of Ti atoms inside the O6 octahedra may be considered to be significantly responsible for the dipole moment: